#list1 = [1,2,3,2]
#a = list1[0]
#for i in list1:
 #   if i > a:
  #      a = i
#print(a)
#list2 = [1,2,3,4,'a',1]
#sum = 0
#for i in list2:
#    if isinstance(i,int):
 #       sum = sum + i
#print(sum)

# x = 5
# for i in range(2,x):
#     if x % i == 0:
#         print("不是素数")
#         break
# else:
    # print("是素数")
x = 10
sum = 0
for i in range(2,x+1):
    for j in range(2,i):
        if i % j == 0:
            break
    else:
        sum = sum + 1
print(sum)